I did some double-checking of the ideas I wrote about in my EIGRP-to-OSPF migration article and accidentally typed show ip ospf route instead of show ip route ospf. The results were amazing: this undocumented command displays the per-area topology calculated by the SPF algorithm, including intra-area routes, inter-area routes, ABRs, ASBRs and external routes.A sample printout from one of my routers is included below:

POP#show ip ospf route
 
            OSPF Router with ID (10.1.0.3) (Process ID 1)
 
    Area 1
 
    Intra-area Route List
*   10.1.0.3/32, Intra, cost 1, area 1, Connected
      via 10.1.0.3, Loopback0
*>  10.1.0.17/32, Intra, cost 65, area 1
      via 10.7.1.1, Serial1/0
 
    Intra-area Router Path List
i 10.0.1.2 [64] via 10.7.1.5, Serial1/1, ABR, Area 1, SPF 3
i 10.0.1.1 [64] via 10.7.1.1, Serial1/0, ABR, Area 1, SPF 3
 
    Inter-area Route List
*>  10.0.1.2/32, Inter, cost 65, area 1
      via 10.7.1.5, Serial1/1
*>  10.0.5.2/32, Inter, cost 129, area 1
      via 10.7.1.5, Serial1/1
 
    Inter-area Router Path List
I 10.0.5.2 [128] via 10.7.1.5, Serial1/1, ASBR, Area 1, SPF 3
I 10.0.5.2 [164] via 10.7.1.1, Serial1/0, ASBR, Area 1, SPF 3
I 10.0.5.1 [128] via 10.7.1.1, Serial1/0, ASBR, Area 1, SPF 3
 
    External Route List
*>  0.0.0.0/0, Ext2, cost 20, tag 1
      via 10.7.1.1, Serial1/0
      via 10.7.1.5, Serial1/1